Everywhere: Use default execpromises argument for Core::System::pledge

Author: https://github.com/bgianfo
Commit: cf4fa936be
Pull-request: https://github.com/SerenityOS/serenity/pull/11106

Userland/Utilities/nproc.cpp

@@ -11,7 +11,7 @@
 
 ErrorOr<int> serenity_main(Main::Arguments)
 {
-    TRY(Core::System::pledge("stdio rpath", nullptr));
+    TRY(Core::System::pledge("stdio rpath"));
     auto file = TRY(Core::File::open("/proc/cpuinfo", Core::OpenMode::ReadOnly));
 
     auto buffer = file->read_all();